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Isothermal process law: identify the governing gas law For an isothermal (constant-temperature) process of an ideal gas, select the correct law that applies. Choose the correct option.

Difficulty: Easy

Boyle's law
Charles' law
Gay-Lussac law
Avogadro's law

Correct Answer: Boyle's law

Explanation:

Concept
For an isothermal process (T constant) of an ideal gas, the pressure–volume product remains constant: pV = constant. This is exactly Boyle's law.

Why the others are incorrect
Charles' law is V ∝ T at constant p; Gay-Lussac's is p ∝ T at constant V; Avogadro's relates equal volumes to equal moles at the same T and p.

Final Answer
Boyle's law

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